Radial Quasiballistic Transport in Time-Domain Thermoreflectance Studied Using Monte Carlo Simulations

Abstract

Recently, a pump beam size dependence of thermal conductivity was observed in Si at cryogenic temperatures using time-domain thermal reflectance (TDTR). These observations were attributed to quasiballistic phonon transport, but the interpretation of the measurements has been semi-empirical. Here we present a numerical study of the heat conduction that occurs in the full 3D geometry of a TDTR experiment, including an interface, using the Boltzmann Transport Equation. We identify the radial suppression function that describes the suppression in heat flux, compared to Fourier's law, that occurs due to quasiballistic transport and demonstrate good agreement with experimental data. We also discuss unresolved discrepancies that are important topics for future study.

References in corpus (4)

• Energy Dissipation and Transport in Nanoscale Devices
• Direct Measurement of Room Temperature Non-diffusive Thermal Transport Over Micron Distances in a Silicon Membrane
• Efficient simulation of multidimensional phonon transport using energy-based variance-reduced Monte Carlo formulations
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Cited by in corpus (11)

• Tutorial: Time-domain thermoreflectance (TDTR) for thermal property characterization of bulk and thin film materials
• Anisotropic Thermal Conductivity of 4H and 6H Silicon Carbide Measured Using Time-Domain Thermoreflectance
• The role of low-energy phonons with mean-free-paths >0.8 um in heat conduction in silicon
• Interfacial Phonon Scattering and Transmission Loss in >1 um Thick Silicon-on-insulator Thin Films
• Heat dissipation in the quasiballistic regime studied using Boltzmann equation in the spatial frequency domain
• Unifying first principle theoretical predictions and experimental measurements of size effects on thermal transport in SiGe alloys
• Modeling ballistic effects in frequency-dependent transient thermal transport using diffusion equations
• Quasiballistic heat removal from small sources studied from first principles
• Analysis of nonlocal phonon thermal conductivity simulations showing the ballistic to diffusive crossover
• Compact models for multidimensional quasiballistic thermal transport
• Relativistic stable processes in quasi-ballistic heat conduction in thin film semiconductors